As Gianluca told you the command to see all the gluster volume settings is :

gluster volume get vol_name all

The previous command you used : gluster volume info vol_name       will list only modified settings from default and not all the settings. The output shows only volume "Options Reconfigured".

Regarding if this is an important bug that affects gluster 7.6(or other versions) and should be disabled by default, i dont know for sure.

I am just using ovirt as a hyperconvergence tool.

Maybe someone from the ovirt developmemt team can answer that.